Pressure actuated fill tube for toilet tanks

ABSTRACT

A pressure actuated fill tube for toilet tanks is taught which is capable of reducing the flow of water into the toilet tank to a minimum rate when a shower or other water use appliance is running, substantially reducing the likelihood of a shower scalding incident if someone flushes the toilet while someone else is in the shower, and allowing the toilet tank to fill over time. Also taught is a means to implement the required pressure sensitive valve as an integral part of the pressure actuated fill tube for toilet tanks. Also taught is a pressure actuated fill system for toilet tanks that is configured with the pressure sensitive valve located inside the toilet tank.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. patent application serial No. 60/285,520, filed Apr. 23, 2001, which application is pending.

FIELD OF THE INVENTION

[0002] This invention relates to a pressure actuated fill tube for toilet tanks that slows the toilet tank fill rate when a shower is in operation, substantially reducing the likelihood of a scalding incident should someone flush the toilet while someone else is taking a shower.

BACKGROUND OF THE INVENTION

[0003] There have been several attempts to address the problem of shower scalding by developing “scald proof” or “self balancing” taps, for example U.S. Pat. No. 5,931,181 issued Aug. 3, 1999 to Cook, et al (assigned to Emhart, Inc.), U.S. Pat. No. 4,877,181 issued Oct. 31, 1989 to Stewart, and U.S. Pat. No. 4,220,175 issued Sep. 2, 1980 to Keller ii, et al, assigned to Kel-Mar Manufacturing. These are all designed to keep the shower temperature constant despite changes in either hot or cold water supply pressure. Other patents teach temperature sensitive shut-off valves that will turn off the shower when the supply temperature exceeds a safe level, for example U.S. Pat. No. 5,878,949 issued Mar. 9, 1999 to Matsui, et al (assigned to Toto Ltd., reference PCT/JP96/02481).

[0004] In contrast, the current invention focuses on the most common cause of these problems, i.e. flushing the toilet while someone is in the shower, and addresses the source of the problem rather than fixing the symptoms at the shower faucet as in current approaches. This is particularly important since a toilet flush can't be easily stopped once initiated.

[0005] It would be desirable to have a pressure actuated fill tube for toilet tanks that would sense the lower cold water pressure caused by a running shower (or any other running water) and control the filling of the toilet until the water pressure is restored. Further, this device must be compatible with existing toilet tank fill tubes and must be easily installed by the average homeowner. Further, this device must be adjustable to adapt to various water pressure situations.

SUMMARY OF THE INVENTION

[0006] Accordingly, the present inventors have devised a pressure actuated fill tube for toilet tanks that is designed to sense a drop in water pressure, such as that caused by a running shower, and control the filling of the toilet tank until such time as the water pressure has been restored. This device will substantially slow the toilet tank fill rate when the shower is on, thereby preventing a noticeable drop in cold water pressure. Under normal circumstances a sudden drop in cold water pressure would change the balance between hot and cold water pressures at the shower faucet, therefore causing the shower to become dangerously hot.

[0007] In its simplest form the device consists of a pressure sensitive valve placed in the middle of or at either end of a standard toilet fill tube. Under normal circumstances the toilet tank will be allowed to fill at a normal rate. When the pressure sensitive valve senses that there is less than normal water pressure, the toilet tank fill rate is throttled back to a very low rate. This will ensure that the toilet tank will eventually become full even in the low pressure scenario, but at a rate that will not noticeably affect the cold water pressure in the system. This minimal rate is also an important feature to ensure that the toilet tank will eventually fill even when the low pressure situation exists for a prolonged time such as when watering a lawn.

[0008] It is important to note that the need for a minimal fill rate also means that the pressure sensitive valve does not need to be of high quality. In other words the pressure actuated fill tube for toilet tanks actually requires a “leaky” valve—i.e. one that never completely shuts off. This characteristic will reduce the cost of the product since the parts may be made of plastic, and perfect valve seats are not a requirement. Further, this characteristic will allow the use of a variety of different types of pressure sensitive valves. Note that a full shut-off valve is already installed as a normal part of most toilet tank fill connections, and may be used when service is required.

[0009] The pressure sensitive valve may be externally adjustable to adapt to various water system situations around the world. The valve may be designed to sense a change in relative pressures such that it will respond to a drop in water pressure from a normal to a minimum threshold level. The minimum threshold pressure represents that lowest pressure that will support the safe operation of the shower, i.e. the pressure at which an incremental drop in pressure could result in a shower scalding incident. The externally accessible user controls may adjust the normal and/or minimum threshold pressure levels, as well as the corresponding flow rates, to match the characteristic requirements of the system in which the pressure actuated fill tube is to be installed.

[0010] The pressure sensitive valve may be an integral component of the fill tube, as described above, to facilitate the installation of the device on existing toilets. Alternatively, the pressure sensitive valve may be configured to be an integral part of new toilets such that standard toilet tank fill tubes may be installed with new toilets so configured to achieve the same results. Further, the pressure sensitive valve may be configured as an integral part of the shut-off valve that isolates the toilet from the main water supply in most installations.

[0011] The pressure actuated fill tube for toilet tanks may also be configured and adapted to control the supply of water to other water use appliances such as clothes washers and lawn sprinklers. These are all devices which, if turned on accidentally when someone is in the shower, can cause a shower scalding incident. The pressure actuated fill would allow these devices to continue to operate at a minimum flow rate level until such time as the shower is turned off.

[0012] In some systems the water supply pressure is sufficient to support several water use appliances, in which case the pressure actuated fill tube for toilet tanks may not respond if the toilet and the shower are operated simultaneously. This is simply because the water pressure in the cold water system remains above the minimum threshold level, most likely due to a higher capacity supply line into the building. In these situations the water pressure may not drop to a minimum threshold level until three or more water use appliances are in operation, at which time the pressure actuated fill tube for toilet tanks will immediately reduce the rate of water flow into the toilet to keep the water pressure at a safe level.

BRIEF DESCRITION OF THE DRAWINGS

[0013] Embodiments of the invention are described by way of example with reference to the following diagrams in which;

[0014]FIG. 1 is a functional view of the pressure actuated fill tube for toilet tanks connected to a water supply and a toilet tank,

[0015]FIG. 2 is a section view of one possible configuration for the pressure sensitive valve,

[0016]FIG. 3 is a top view of the valve seat showing the minimum flow rate channels, and

[0017]FIG. 4 is a functional view of a pressure actuated fill system for toilet tanks with a pressure sensitive valve internal to the toilet tank.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0018]FIG. 1 illustrates a pressure actuated fill tube for toilet tanks 2 connected between shutoff valve 8 and toilet tank 6. Under normal circumstances water will flow from water supply 4 through shut-off valve 8, inlet tube 10, pressure sensitive valve 12, outlet tube 14, and into toilet tank 6. Pressure actuated fill tube for toilet tanks 2 is comprised of inlet tube 10, pressure sensitive valve 12, outlet tube 14, and the associated standard fittings to attach to shutoff valve 8 and toilet tank 6. Pressure actuated fill tube for toilet tanks 2 is designed to compatibly replace standard toilet tank fill tubes.

[0019] When water pressure 18, which is in communication with pressure sensitive valve 12, drops below a minimum threshold level, pressure sensitive valve 12 will substantially close to reduce the flow of water into toilet tank 6 to a minimum level. When water pressure 18 returns to a normal level, then pressure sensitive valve 12 will re-open allowing toilet tank 6 to fill at a normal rate. In either case the water level 20 in toilet tank 6 will be controlled by flush mechanism 19 contained within toilet tank 6, and the water flow will be automatically shut off at the appropriate water level 20.

[0020] Threshold pressure adjustment screw 16 allows pressure sensitive valve 12 to respond at different minimum threshold pressures. This adjustment is required to allow the pressure actuated fill tube for toilet tanks 2 to function properly in water systems with different normal water pressures and minimum threshold pressure requirements. Over the long term, threshold pressure adjustment screw 16 may be used to compensate for mechanical or other changes within pressure actuated fill tube for toilet tanks 2, or changes in the normal water pressure over time.

[0021]FIG. 2 is a section view of one possible configuration for pressure sensitive valve 12. Inlet tube 10 and outlet tube 14 may be sealed together to form the body of pressure sensitive valve 12 as shown. Pressure sensitive valve seat 30 is an integral part of inlet tube 10.

[0022] Under normal circumstances, i.e. when water pressure 18 is above the minimum threshold level, pressure sensitive valve ball 32 will be pushed away from pressure sensitive valve seat 30 such that water will be able to flow freely through the space created between pressure sensitive valve ball 32 and pressure sensitive valve seat 30 as shown in FIG. 2.

[0023] When water pressure 18 drops below the minimum threshold level, pressure sensitive valve spring 34 pushes pressure sensitive valve ball 32 back into pressure sensitive valve seat 30, substantially reducing the flow of water between the two components. Valve spring 34 will hold pressure sensitive valve ball 32 in the minimum flow position until such time as water pressure 18 returns to the threshold level.

[0024] The force exerted by pressure sensitive valve spring 34 onto pressure sensitive valve ball 32 may be adjusted by raising or lowering spring plate 36. Spring plate 36 has a hole in the middle to allow the through flow of water, and is held in place between pressure sensitive valve spring 34 and actuator cams 38 which are in direct mechanical communication with threshold pressure adjustment screw 16. A turn of threshold pressure adjustment screw 16 will rotate actuator cams 38 which will either allow spring plate 36 to rise, reducing the force exerted by pressure sensitive valve spring 34 on pressure sensitive valve ball 32, or push spring plate 36 down, having the opposite effect. The former action will cause pressure sensitive valve 12 to respond at a lower minimum threshold water pressure, and the latter action will cause pressure sensitive valve 12 to respond at a higher minimum threshold water pressure.

[0025] Threshold pressure adjustment screw 16 may be inserted into outlet tube 14 as a first step in the manufacturing process. (O-ring 37 prevents leaks around the head of threshold pressure adjustment screw 16.) Actuator cams 38 may be affixed to threshold pressure adjustment screw 16 to hold it in place. Then, spring plate 36 is inserted into the open end of outlet tube 14 along with pressure sensitive valve spring 34 and pressure sensitive valve ball 32. Finally, inlet tube 10 is bonded and sealed in place over the open end of outlet tube 14.

[0026]FIG. 3 is a top view of pressure sensitive valve seat 30 showing the minimum flow rate channels 39. The minimum flow rate channels 39 are designed to allow a small amount of water to flow past pressure sensitive valve ball 32 (reference FIG. 2) when pressure sensitive valve ball 32 is pressed into pressure sensitive valve seat 30. This minimum flow rate is designed to allow the toilet tank to fill very slowly without noticeably affecting the balance of cold and hot water pressures within the water system (toilet tanks are filled from the cold water side of the system). The same result could be achieved using other methods, for example by molding a small protrusion in pressure sensitive valve seat 30 such that pressure sensitive valve ball 32 will not seat properly, or molding pressure sensitive valve ball 32 with similar channels or imperfections. It can be readily deduced that pressure sensitive valve ball 32 and pressure sensitive valve seat 30, although they may resemble a standard valve assembly, do not need to completely seal against water flow and can therefore be manufactured quite inexpensively.

[0027]FIG. 4 illustrates a pressure actuated fill system for toilet tanks 40 that allows for the use of standard toilet tank fill tube 44 connected between shut-off valve 8 and toilet tank 6. Under normal circumstances water will flow from water supply 4 through shut-off valve 8, standard toilet tank fill tube 44, internal fill tube 50, and into combined pressure sensitive valve and flush mechanism 48. Combined pressure sensitive valve and flush mechanism 48 contains internal pressure sensitive valve 42.

[0028] When water pressure 18, which is in communication with internal pressure sensitive valve 42, drops below a minimum threshold level, internal pressure sensitive valve 42 will substantially close to reduce the flow of water into toilet tank 6 to a minimum level. When water pressure 18 returns to a normal level, then internal pressure sensitive valve 42 will re-open allowing toilet tank 6 to fill at a normal rate. In either case the water level 20 in toilet tank 6 will be controlled by flush mechanism contained within combined pressure sensitive valve and flush mechanism 48, and the water flow will be automatically shut off at the appropriate water level 20.

[0029] Internal threshold pressure adjustment screw 46 allows internal pressure sensitive valve 42 to respond at different minimum threshold pressures. This adjustment is required to allow the pressure actuated fill system for toilet tanks 40 to function properly in water systems with different normal water pressures and minimum threshold pressure requirements. Over the long term, internal threshold pressure adjustment screw 46 may be used to compensate for mechanical or other changes within pressure actuated fill system for toilet tanks 40, or changes in the normal water pressure over time.

[0030] Combined pressure sensitive valve and flush mechanism 48 may be used to repair faulty toilets when the existing flush mechanism fails, or it may be used as an OEM part when manufacturing new toilets. In both cases the resulting pressure actuated fill system for toilet tanks 40 may be implemented with a standard toilet tank fill tube 4.

[0031] The internal pressure sensitive valve 42 contained within combined pressure sensitive valve and flush mechanism 48 will have the same function as pressure sensitive valve 12 contained within pressure actuated fill tube for toilet tanks 2 (reference FIG. 1), however it may be of simpler design. This is primarily because the seals around internal threshold pressure adjustment screw 46 do not need to be of the same quality as the seals around threshold pressure adjustment screw 16 (reference FIG. 1), and in some situations may not be required at all.

[0032] The seals around internal threshold pressure adjustment screw 46 will not be required in situations where internal pressure sensitive valve 42 is positioned downstream from the flush mechanism shut-off valve contained within combined pressure sensitive valve and flush mechanism 48. This is because a flush mechanism shut-off valve configured in this manner will positively stop the further flow of water once appropriate water level 20 is reached, and any leaks around internal threshold pressure adjustment screw 46 will simply flow into toilet tank 6 during the filling process. These leaks are useful in that they will contribute to the minimum flow rate requirement. This greatly simplifies the design of internal pressure sensitive valve 42, and as a result it may be implemented as an internal component of combined pressure sensitive valve and flush mechanism 48 at very low cost. Several combined pressure sensitive valve 1 flush mechanism designs are possible with this principle in mind.

[0033] The pressure actuated fill tube and pressure actuated fill system for toilet tanks of the present invention allow for many applications, and may be implemented with various types of pressure sensitive valves. Although reference is made to the embodiments listed above, it should be understood that these are only by way of example and to identify the preferred use of the device known to the inventors at this time. It is believed that the pressure actuated fill tube and pressure actuated fill system for toilet tanks have many additional uses and implementations which will become obvious once one is familiar with the fundamental principles of the invention. 

We claim:
 1. A pressure actuated fill tube for toilet tanks comprising: a. An inlet tube, b. A pressure sensitive valve that is responsive to changes in water supply pressure, and c. An outlet tube. Said inlet tube directing the flow of water from the water supply system into said pressure sensitive valve, said pressure sensitive valve controlling the flow of water between a minimum flow rate and a maximum flow rate, and said outlet tube directing the controlled flow of water into said toilet tank.
 2. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said minimum flow rate is equal to or greater than zero gallons per minute, and wherein said minimum flow rate is less than said maximum flow rate.
 3. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein at least said minimum flow rate will always be allowed to flow through said pressure sensitive valve.
 4. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said minimum flow rate will fill said toilet tank over time while having a minimal affect on the water pressure within said water supply system.
 5. The pressure actuated fill tube for toilet tanks as claimed in claim 1 further comprising an adjustment mechanism, wherein said pressure sensitive valve responds at an adjustable minimum threshold water supply pressure as determined by said adjustment mechanism.
 6. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said inlet tube is connected to a standard toilet tank shut-off valve or other standard toilet water supply plumbing attachment.
 7. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said outlet tube is connected to a standard toilet plumbing attachment.
 8. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said pressure sensitive valve may be adaptively configured as a stand-alone component that may be attached at either end of a standard toilet tank fill tube.
 9. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said pressure sensitive valve may be adaptively configured as an integral part of the shut-off valve that isolates the toilet from the main water supply in most installations.
 10. The pressure actuated fill tube for toilet tanks as claimed in claim 1 further configured and adapted to control the supply of water to clothes washing machines, lawn sprinklers, and other water use appliances.
 11. The pressure actuated fill tube for toilet tanks as claimed in claim 1 wherein said pressure sensitive valve is further comprised of; a. a valve seat, b. a valve ball, c. a valve spring, d. a spring plate, and e. an actuator cam. Wherein said actuator cam acts on said spring plate to adjust the pre-load on said valve spring, and wherein said valve spring with said adjustable pre-load holds said valve ball firmly in said valve seat until such time as said input water pressure rises above said minimum threshold level to counteract said pre-load on said valve spring to move said valve ball away from said valve seat.
 12. The pressure actuated fill tube for toilet tanks as claimed in claim 11 wherein said valve plate has a hole to allow the through flow of water.
 13. The pressure actuated fill tube for toilet tanks as claimed in claim 11 wherein said actuator cam is in communication with an externally accessible set screw, and wherein said set screw is sealed against leaks with o-rings.
 14. The pressure actuated fill tube for toilet tanks as claimed in claim 11 wherein said pressure sensitive valve is configured with an imperfect said valve seat, and wherein said imperfect valve seat allows said minimum flow rate to flow past said valve ball when said pressure sensitive valve is closed.
 15. The pressure actuated fill tube for toilet tanks as claimed in claim 11 wherein said valve seat contains minimum flow rate channels and wherein said minimum flow rate channels allow said minimum flow rate to flow past said valve ball when said pressure sensitive valve is closed.
 16. The pressure actuated fill tube for toilet tanks as claimed in claim 11 wherein said inlet tube and said outlet tube are further configured to form the body of said pressure sensitive valve.
 17. The pressure actuated fill tube for toilet tanks as claimed in claim 11 further configured and adapted to control the supply of water to clothes washing machines, lawn sprinklers, and other water use appliances.
 18. A pressure actuated fill system for toilet tanks comprising: a. A standard toilet tank fill tube connected between a standard toilet tank shut-off valve and a standard toilet tank, and b. An integrated pressure sensitive valve, internal to said standard toilet tank, which is responsive to changes in water supply pressure. Said standard toilet tank fill tube directing the flow of water into said standard toilet tank through said integrated pressure sensitive valve, said integrated pressure sensitive valve controlling the flow of water between a minimum and a maximum flow rate.
 19. The pressure actuated fill system for toilet tanks as claimed in claim 18 wherein said minimum flow rate is equal to or greater than zero gallons per minute, and wherein said minimum flow rate is less than said maximum flow rate.
 20. The pressure actuated fill system for toilet tanks as claimed in claim 18 wherein at least said minimum flow rate will always be allowed to flow through said pressure sensitive valve.
 21. The pressure actuated fill system for toilet tanks as claimed in claim 18 wherein said minimum flow rate will fill said toilet tank over time while having a minimal affect on the water pressure within said water supply system.
 22. The pressure actuated fill system for toilet tanks as claimed in claim 18 further comprising an adjustment mechanism, wherein said pressure sensitive valve responds at an adjustable minimum threshold water supply pressure as determined by said adjustment mechanism.
 23. The pressure actuated fill system for toilet tanks as claimed in claim 18 wherein said pressure sensitive valve is an integral part of the flush mechanism contained within said standard toilet tank.
 24. The pressure actuated fill system for toilet tanks as claimed in claim 18 wherein said pressure sensitive valve is an integral part of the flush mechanism contained within said standard toilet tank and wherein said pressure sensitive valve is positioned downstream from the flush mechanism shut-off valve; said pressure sensitive valve being further configured with an adjustment mechanism, wherein said pressure sensitive valve responds at an adjustable minimum threshold water supply pressure as determined by said adjustment mechanism, wherein said adjustment mechanism is not sealed against leaks, and wherein said leaks contribute to said minimum flow rate.
 25. The pressure actuated fill system for toilet tanks as claimed in claim 18 further configured and adapted to control the supply of water to clothes washing machines, lawn sprinklers, and other water use appliances. 